I've really been getting on with one of the girls in my new department at work. Thing is I have no idea if she's friendly or slightly flirty.

Going to see where this goes over the next few weeks, but if you go for it at work and get it wrong at best you make a mistake, and it's a little odd in the office for a few weeks. At worst, I've totally misread the situation and it gets seen as harassment and I'm in HR!